This invention concerns a machine with handling assemblies to package layers of bars.
To be more exact, the invention concerns a machine with handling assemblies which is suitable to engage layers of bars arriving continuously on a conveyor belt, to overturn every second layer by 180.degree. about the lengthwise axis of the layer and to package the layers in appropriate collection positions so as to form packages of alternate non-inverted/inverted layers.
By the word "bars" hereinafter are meant bars having a simple profile or bars of a complex figure or sections.
To be more exact, the packaging machine with handling assemblies comprises two pluralities of handling assemblies, each assembly being able to rotate about its own axis to engage and deliver the layers of bars.
The packaging machine with handling assemblies according to the invention is especially advantageous for the stacking of layers of angle irons since it enables the angle irons to be fitted on each other in a vertical direction.
The packaging machine with handling assemblies according to the invention is applied advantageously in a packaging zone downstream of a production line, especially a rolling line.
The state of the art covers machines to package bars, whether the bars are rolled or extruded, flat or sections, etc.
DE-B-l.183.020 discloses a device to stack bars, whereby each layer has to be overturned by 180.degree. about the lengthwise axis of the bars so that packages can be formed with the layers fitted one on top of another. This device comprises a lifting rake which conveys the bars onto a depositing table which can be moved by a link guide. Orientable arms equipped with electromagnets take the bars from the depositing table and arrange them on a stacking bench.
Other devices to stack rolled bars by using electromagnets able to lift the bars or rolled sections are disclosed in DE-B-1.235.811, DE-B-1.258.796 and DE-B-31.296.578. All the above known devices entail drawbacks and shortcomings due to the complexity and cost of the lifting and conveying elements and the relatively long conveying times, which generally do not permit continuous engagement of bars arriving from the feeder conveyor belt.
This entails delays and downtimes in the subsequent shops in view of the high speeds of modern rolling trains and resulting high output.
Moreover, the known systems have a great overall bulk, take up a large area and entail high maintenance costs owing to the complexity of the mechanisms, long cycle times, heavy working costs and considerable installed power.
IT-A-83465/89 discloses a rotary packaging machine fed with defined layers of bars; the machine comprises a plurality of pairs of claws able to rotate about a lengthwise axis parallel to the package being formed; the claws lie on a plane passing through that axis and radial thereto; the axis of rotation lies between the two planes of axial arrival of the sections, and the claws are secured to rotary means.
This solution entails the shortcoming that, when packages are being formed with alternate non-inverted/inverted layers, the bars have to reach the packaging machine already formed in two layers face to face and butted but suitably separated sideways, thus increasing the overall lateral bulk of the device. Moreover, the above packaging machine is fed by feeding lengthwise the bars to be packaged, and this involves long cycle times when the sections have a considerable length.
IT-B-1.221.723 discloses a device to stack layers of bars which entails the problem of forming only packages in which none of the layers are inverted.